Not entirely sure what you are asking but the 'F' in fps stands for frames.

Frames per second don't affect how fast or slow your video plays, it makes panning and movement of the footage smoother.

Your video camera is basically a still camera, taking 30 or 60 photos in one second, and then stitching it together for you.

Remember at school, drawing stickmen on the corners of your notepad, then flicking through the notepad with your thumb to make the stickman move?

The more pages you draw on, the smoother the stick man moves. It's the same with frame rates, the more frames per second in your video, the smoother the video.

If you record something at 60 frames per second, you need to make sure after you edit, you render (export/save) at 60fps too.

Hope that helps.

Also, further to the OP, every upload to a website invariably results in compression and conversion. There are a massive amount of video file formats and many websites convert to a standard one. They also will frequently compress the video to save storage space and download times.

Both these processes can result in weird stuff happening as some formats convert better to one than another.

This can speed up and slow down vids as well as the previous mentioned pixelation and striation of the image. I spend my days converting video and getting a smooth, high quality image in a small file size is the bane of my existence.

In a nutshell: always use "p", never "i" modes. And 50p/60p is nice and work well with youtube, vimeo, etc...

More detailed: In the old analogic TV times, video was recorded at 60 images (frames) per second - fps - (60fps for NTSC, 50fps for PAL used in europe)
However the hardware used was not able to handle 60 full images per seconds, so there was many cheats, among which only transmitting only half of the image in each frame: in one frame you get the even lines, in the other the odd ones. So a full image will come only 30 times per second. But since we now have digital TV you can forget about all this nonsense.

This is the "i" mode, for "interlaced". "p" is the normal mode we use now: full images in each frame.
The problem with interlaced was that since the filmed subject moves, two consecutive frames are not half of the same image! so there is no way to get back a proper full image for use on computer from an "i" mode: never use them!

Also, less than 60 images per second, and the eye will perceive a flicker (actually the limit is more towards 90fps). This is why non-digital movies in theater, which are recorded at 24 fps "p", get the frames doubled: they are shown at 48fps, each frame being shown twice... which is why panning in non-digital movies seem to stutter.

So, ideally, 90p should be the norm. but 50p/60p is quite excellent, 25p/30p is somewhat OK with our modern LCD screens.

colas said...
In a nutshell: always use "p", never "i" modes. And 50p/60p is nice and work well with youtube, vimeo, etc...

More detailed: In the old analogic TV times, video was recorded at 60 images (frames) per second - fps - (60fps for NTSC, 50fps for PAL used in europe)
However the hardware used was not able to handle 60 full images per seconds, so there was many cheats, among which only transmitting only half of the image in each frame: in one frame you get the even lines, in the other the odd ones. So a full image will come only 30 times per second. But since we now have digital TV you can forget about all this nonsense.

This is the "i" mode, for "interlaced". "p" is the normal mode we use now: full images in each frame.
The problem with interlaced was that since the filmed subject moves, two consecutive frames are not half of the same image! so there is no way to get back a proper full image for use on computer from an "i" mode: never use them!

Also, less than 60 images per second, and the eye will perceive a flicker (actually the limit is more towards 90fps). This is why non-digital movies in theater, which are recorded at 24 fps "p", get the frames doubled: they are shown at 48fps, each frame being shown twice... which is why panning in non-digital movies seem to stutter.

So, ideally, 90p should be the norm. but 50p/60p is quite excellent, 25p/30p is somewhat OK with our modern LCD screens.

25 is completely adequate for smooth motion which is why it was adopted so widely. Most of the world uses it.

Pal is not 50 fps unless it is interlaced, for exactly the reasons you mentioned. Standard Pal, with a full image per frame, is 25.

720 is good enough. 60fps is overkill IMO. Any homemade movies are too crap to need high frame rates and super resolution.

Are you exporting it as an Avi or some other video format before trying to upload it to Vimeo? Or are you doing directly from iMovie (which is a crap program anyway - imovie 6 was the last really good version)? Exporting it would probably be the go.

If you can, Adobe Premiere, Final Cut and a couple of others for a couple of hundred bucks are far better than any proprietary software.

Apple started dumbing down iMovie when movies such as Tarnation started getting cinema releases after being edited on iMovie6. They wanted to sell more copies of Final Cut. I run a suite of 9 IMacs for video editing and use Adobe Premiere. I just find it a bit more user friendly than Final Cut and way more than Pinnacle. It's probably not quite as stable though. And you probably need more time rendering. But titling and customising effects is easier.

drift said...
When was NTSC ever 30 fps?
it was always 29.97 fps hence why it was always costly to go from PAL TO NTSC or vice versa.
720p@50 is more than good enough if the content is well shot

Yep.